JP2009162049A - Method of discharging silted deposit in reservoir - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To efficiently discharge silted deposit by the release of a floor discharge gate while adjusting pressure distribution by a water current. <P>SOLUTION: This method of discharging sediment deposited at the bottom of a reservoir 2 dammed up by a dam 12 is carried out by repeating the operation of opening the flood discharge gate 14 corresponding to the deepest position of water depth first in the dam 12 provided with a plurality of flood discharge gates 14 in a lateral row, to discharge the silted deposit in the position and its periphery downstream along with a water current while scouring and crumbling the silted deposit in sequence, then closing the flood discharge gate 14 and opening the floor discharge gate 14 located next. The water current is thereby converged on one place, and the sediment deposited around the position of each gate is discharged downstream along with the water current while being scoured and crumbled. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a method for discharging sediment sediment in a reservoir dammed up by a dam.

  In a reservoir formed by damming a river with a dam, if a large amount of sediment including mud generated by construction upstream of the river flows into the reservoir, they will sink into the reservoir, causing a sedimentation phenomenon and reducing the amount of stored water Cause.

  As a means of suppressing this sedimentation phenomenon, there is a method of removing sediment through a reservoir.

  As another means, there is a method of opening a spillway gate provided in a dam, winding up sediment by the pressure, and discharging it to the downstream side together with the discharged water.

Japanese Patent Laid-Open No. 03-115613 JP 2003-261924 A JP 2003-64649 A Japanese Patent Laid-Open No. 10-060871

  In the former dredging method, the dredging machine removes the sediment deposited on the riverbed evenly. However, if the amount of inflowing sediment is large, the amount of construction and the number of constructions increase, so the construction cost is extremely high.

  Moreover, in the latter method of opening the spillway gate, a method of sequentially opening a plurality of spillway gates, for example, from the right bank side to the left bank side is employed. However, there is a problem that a sufficient sedimentation effect cannot be obtained because the sediment component of sediment has not yet been discharged. Moreover, the problem of muddy water on the downstream side also occurred along with the discharge and discharge.

  The present invention solves the above-mentioned problems, and its purpose is to devise the distribution of pressure due to water flow, so that sediment sediment can be discharged and discharged efficiently by releasing the spillway gate. A method is provided.

  In order to achieve the above object, the present invention provides a dam in which a plurality of spillway gates are arranged in a horizontal row, and by first opening the spillway gate whose water depth corresponds to the deepest position, sedimentary sediment at the position and the periphery thereof is opened. The scouring and collapsing are discharged to the downstream side along with the water flow, and then the spill gate is closed and the adjacent spill gate is released to concentrate the water flow at only one location. It is characterized by discharging the sediment accumulated in the vicinity of the position to the downstream side along with the water flow while sequentially scouring and collapsing.

  According to the present invention, the water flow is concentrated in one place by sequentially opening and closing from the gate where the water depth is deep and the flow momentum is strong, and the sediment deposited in an unevenly distributed state is discharged to the downstream side together with the water flow. The water depth can be recovered.

(A)-(c) is a side view which shows the sedimentation condition and dredging work in the reference example of this invention method. (A)-(f) is explanatory drawing which shows transition of the deposition state in the embodiment. It is a plane explanatory view showing the earth and sand accumulation situation by one embodiment of the present invention. It is AA sectional view explanatory drawing of FIG. (A)-(d) is sectional drawing for description which shows transition of the sediment accumulation state in the embodiment.

Hereinafter, reference examples and embodiments of the present invention will be described in detail with reference to the accompanying drawings. 1 and 2 show a reference example of the present invention.

  In the figure, a dam 1 is constructed on the rock in the valley where the river flows, and a reservoir 2 is located upstream of the dam. In addition, although what is less than 15m in height is called a weir, here, it is called a dam collectively. There are various types of dams 1 such as gravity dams, arch dams, buttress dams, etc., any of which can be used, each of which has a spillway gate 3 and, if necessary, opens this gate 3 to create a reservoir. The water stored in 2 can be discharged.

  In FIGS. 1 (a) and 2 (a), sediment 5 carried from the upstream is accumulated on the bottom of the reservoir 2, that is, the river bed 4, and the amount of stored water is reduced due to the sedimentation phenomenon. It is shown.

In this reference example , as shown in FIG. 1 (b), first, the dredger 6 and the earth carrying ship 7 are introduced into the reservoir 2, and the excavated earth and sand are loaded into the earth carrying ship 7 while performing the dredging work.

  Although the illustrated dredger 6 is a grab type, a conveyor bucket type or a pump type can also be used. Further, in a place where the reservoir area is small and the dredger 6 cannot be introduced, it is possible to use a civil engineering machine such as a backhoe, or If the water depth is shallow, you may go directly into the reservoir and perform excavation work.

  In the initial stage, the surface layer of the earth and sand 5 is uniformly crushed. This is because small particles such as mud and fine sand suspended by the dam 1's damming action settle mainly on the surface layer and cause turbid water at the time of subsequent discharge.

  Thereafter, as shown in FIG. 1 (b), an artificial waterway 8 having an inverted trapezoidal cross section is formed in one place as an inclined surface having a gentle gradient that gradually becomes shallower from directly below the dam 1 to the upstream side. FIG. 1C and FIG. 2B show the construction completion state of the water channel 8.

  After the dredging operation is completed and the dredger 6 and the excavation ship 7 are withdrawn, when the gate 3 is opened, the water pressure in the water channel 8 is higher than that in other places as shown by the arrow in FIG. 2 (d) and (e), the soil around the water channel 8 is carried by the water stream to the downstream side of the dam 1 while expanding the water channel 8 due to scouring and collapse due to water pressure. leak.

  Eventually, as shown in FIG. 2 (f), the original depth of water can be almost recovered while leaving a large amount of gravels that cannot be carried by the water flow in the river bed 4. After the gate 3 is closed, a predetermined value is obtained. Water can be stored in the reservoir 2 in a state in which the water depth is secured.

  During discharge, mud, fine sand, etc. are roughly removed in advance during the dredging process, and there are many components that are relatively easy to settle. The influence on the side can be minimized.

3 to 5 show a Kazumi facilities embodiment of the present invention. First, as shown in FIG. 3, in a meandering river, the meandering side having a large curvature is likely to be eroded 10, and earth and sand 11 is likely to be deposited on the small side.

  In the case where the dam 12 is constructed downstream, for example, as shown in a cross-sectional view in FIG. 4, at the position directly above the dam 12, the sediment earth and sand 11 is unevenly distributed on the right bank side where the meandering curvature is small, and toward the left bank side. And accumulated in an inclined state. As a result, the deepest waterway is formed on the left bank.

  In order to open the spillway gate and discharge the sediment from this state, for example, when four spillway gates 14 are provided in a horizontal row as shown in FIG. By opening 14, water pressure concentrates on the opened discharge port 14 a, and the sediment deposited in the vicinity of the discharge port 14 a is scoured by the water flow and discharged downstream by the water flow. 11 is discharged downstream while collapsing.

  After that, the gate 14 is closed, and as shown in FIGS. 5B to 5D, the release of the gate 14 is sequentially moved to the right bank side, thereby concentrating the water flow on each discharge port 4a. The earth and sand near the discharge port 14a is discharged, and in the final state, as shown in FIG. 5 (e), the earth and sand 11 deposited in an unevenly distributed state upstream of the dam 14 is almost wiped out.

1,12 Dam 2 Reservoir 3,14 Spillway gate 5,11 Sediment sediment 8 Waterway

Claims (1)

In a dam with multiple spillway gates in a horizontal row, the spillway gate with the water depth corresponding to the deepest position is opened first. To release
Then, by closing the spillway gate and repeating the operation to release the spillway gate located next to it, the water flow is concentrated only in one place, and the sediment deposited in the vicinity of each gate position is sequentially washed and collapsed. A method for discharging sedimentary sediment in a reservoir, characterized in that it is discharged downstream.

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